<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
<style>
    *{
        margin: 0px;
        padding: 0px;
    }
   .fija{
    border: 1px solid red;
    width: 800px;
    margin: 0% auto;
   }
   .ipok{
    border: 1px solid blue;
    width: 800px;
    margin: 0px auto;
   }
</style>
</head>
<body>
<div class="fija">
    <h3>水果</h3>
    <ul>                        
        <li>香蕉</li>
        <li>苹果</li>
        <li>柠檬</li>
        <li>橙子</li>
    </ul>
</div>
<div class="ipok">
    <h3>人员</h3>
    <ul>
        <li>张三</li>
        <li>牛四</li>
        <li>李五</li>
        <li>马六</li>
    </ul>
</div>
</body>
</html>